As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to these users is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may vary with respect to the type of information handled; the methods for handling the information; the methods for processing, storing or communicating the information; the amount of information processed, stored, or communicated; and the speed and efficiency with which the information is processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include or comprise a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Computer systems, including servers and workstations, are often grouped in clusters to perform specific tasks. A server cluster is a group of independent servers that is managed as a single system and is characterized by high availability, manageability, and scalability, as compared with groupings of unmanaged servers. At a minimum, a server cluster includes two servers, which are sometimes referred to as nodes. In some configurations, the nodes or servers of the cluster are coupled to shared storage. The storage is known as shared storage because it is accessible by each of the nodes of the cluster. In a server cluster having two nodes, both of the nodes would be able to access the shared storage resources.
The nodes of the server cluster communicate with one another to manage the operation of the cluster server and the shared storage resources. In some configurations, the nodes of the server cluster communicate with each other through a communications link that passes through the shared storage resources. As an example, the shared storage resources may comprise multiple disk enclosures housing, each of which may house one or more storage drives. The nodes of the server cluster may communicate with one another by transmitting communications via the communications links that interconnect the multiple disk enclosures of the shared storage resources.
If communication links between disk enclosures are broken or otherwise inoperative, the nodes of the server cluster may be prevented from communicating with one another. In this circumstance, even though the nodes of the server cluster cannot communicate with one another, the nodes may nevertheless be able to access at least a portion of the shared storage resources. Because the nodes of the server cluster cannot communicate with one another, the nodes cannot collectively manage the logical ownership of shared storage resources or changes to the configuration of the shared storage resources. As such, one node can make changes to the logical ownership of shared storage resources or changes to the configuration of the shared storage resources without notifying or receiving the approval of the other node. In this state, a split brain condition can occur in which there is a risk of corrupting the data, the disk configuration, or both.